U.S. Pat. No. 3,629,455 describes a method of controlling hookworms and tapeworms with 1-phenyl-3-alkanimidoylureas having the formula ##STR3## where R is alkyl; and R' is hydrogen or lower alkyl.
U.S. Pat. No. 4,039,575 describes 1-phenyl-3-alkanimidoylthioureas having the formula ##STR4## wherein X is 2-, 3-, or 4-chloro, 2- or 4-bromo, 4-fluoro, 4-iodo, 4-methyl, 4-methoxy, or 4-trifluoromethoxy; a is 1 or 2; R.sub.1 and R.sub.2 are both hydrogen or methyl; and b is 0-4; acid-addition salts thereof; and compositions thereof.
U.S. Pat. No. 3,699,110 describes pyridylaminidinoureas having the formula ##STR5## wherein x is oxygen or sulfur and R is alkyl having from 1 through 8 carbon atoms, alkenyl having from 3 through 6 carbon atoms, cycloalkyl having 3 through 6 carbon atoms, phenyl or benzyl. The terms "benzyl" and "phenyl" include substituted and unsubstituted aryl groups. Representative ring substituents are halo, nitro, trichloromethyl, methyl and the like. The alkyl group in these compounds can be methyl, ethyl, normal propyl, isopropyl, normal butyl, secondary butyl, tertiary butyl, normal pentyl, isopentyl and the various forms of hexyl, heptyl and octyl.